Generally, fuel injection systems, both for diesel engines employing glow plugs and gasoline engines employing spark plugs, are well known in the art. However, no, prior art devices are known which combine a variably controlled injection of fuel directly past the fuel ignition element, sometimes referred to herein as an FIE, initiation (advance or retard) and duration of fuel injection is electronically computed and controlled in order to determine the output power of the engine.
The known prior art fuel injection systems are substantially stoichiometric in nature in that the fuel is injected in response to a controlled volume of inducted air. Rather, the fuel is injected in a manner to first fill the firing chamber in a substantially uniform mixture of fuel and air, thus allowing subsequent burning of the fuel to be comparatively uncontrolled in that such burning can occur progressively along various different paths within the firing chamber. Thus, these prior art fuel injection systems do not effectively control the burning rate of the fuel but rather permit burning to be initiated by an adiabatic temperature rise which spreads unevenly throughout the firing chamber, thus producing inefficient burning of the fuel and often causing a phenomena commonly known as "knocking" or "pinging" which is presently controlled by fuel additives, many of which have been shown to be environmentally hazardous.
The aforementioned method of mixing fuel and air substantially uniformly in the firing chamber and in the approximately correct proportion so that all of the fuel and all of the oxygen in the firing chamber combine during burning is known, as mentioned above, at least, an approximate stoichiometric mixture. In other words, each molecule of gasoline theoretically will combine with a sufficient number of oxygen molecules so that a minimum of fuel or oxygen remains after burning of the fuel is completed. As indicated above, this stoichiometric mixture of fuel and air is not only extremely difficult to obtain but also does not produce the controlled burning of the fuel required to provide the greatest and most efficient production of power with the least damage to the engine.
Reference is made to page 171 of a publication entitled "Foundations of College Chemistry," 2nd Edition, by Hein, published in 1970 by Dickinson Publishing Company of Belmont, California, which states that, "the student . . . should solve each problem by . . . being certain that equations are balanced and mathematical calculations are accurate . . . This section of chemistry, based on weight and mole relationships of chemical formulas and equations, is commonly called stoichiometry."
In prior art gasoline engines employing fuel injection, burning does not begin until the spark occurs, by which time the gasoline has become diffused through the firing chamber and is, in effect, an approximate stoichiometric mixture of gasoline and air (oxygen). The aforementioned will occur even if the advance timing and duration of the fuel injection is controlled electronically.
In prior art diesel engines using fuel injection, the fuel is first injected and then compressed to the point where it self-ignites. By the time the fuel ignites, however, it has become an approximate mixture, even with electronic computation of the fuel injection time duration and amount of advance.
It would make a definite advance in the art to provide an almost completely non-stoichiometric fuel injection system in which the fuel is injected, under the control of an electronically controlled timing system, towards a constantly heated ignition source and therefore is burned substantially uniformly from the beginning to the end of the fuel injection period without first diffusing generally with the air in the firing chamber. The time duration of the fuel injection and the degree of advance can be determined by the electronically controlled timing system of the present invention.
There exists in the prior art one type of fuel injector/ignitor device (an IID), which combines a glow plug (GP) with a compression actuated fuel injector (CAFI), and which is quite compatible with the present invention. This IID is the subject of a pending U.S. patent application filed by George D. Elliott, the inventor of the present invention, Ser. No. 904,378, filed September 8, 1986, entitled "Fuel Injector", and incorporated in its entirety by reference herein.